New YorK AGRICULTURAL EXPERIMENT STATION. 19g 
acidity possessed by casein and the question is important as to 
which is most nearly correct. In most of the work done, phen- 
olphthalein is the indicator commonly used. By making use of 
electrical conductivity measurements, it was possible to determine 
the acidity with great accuracy, independently of indicators. It 
was found that the results agree closely with those obtained when 
phenolphthalein is used, thus confirming the use of this reagent 
in cases involving the acidity of casein. The matter is one of 
practical importance in determining the acidity of milk and milk 
products, in which the acidity of casein is to be determined. 
ENTOMOLOGICAL DEPARTMENT. 
Commercial miscible oils for treatment of the San Jose scale.— 
This bulletin contains the details of a number of experiments with 
proprietary miscible oils to determine their merits for the control 
o1 we San Jose scale. inese preparations contain more or less 
mineral oil, which has been combined with an emulsifying agent 
to facilitate a uniform dilution with water, and are supposed to 
be safer sprays than clear oils alone for the treatment of orchard 
tree.. The miscible oils that were use were Kil-o-Scale, Scalecide 
and Surekill, which were tested in varying proportion on 1,369 
trees, divided among three orchards. In these tests, applications 
of miscible oils at the recommended proportions of one part to 
twenty or twenty-five parts of water failed to give uniform results 
on scale. The trees receiving these treatments usually showed more 
or less spotting of the fruit and varying infestation of the new 
growth. Miscible oils in the proportion of one part of oil to ten 
or fifteen parts of water, while uniformly more destructive to the 
scale than the weaker preparations, were usually not quite so 
effective as the boiled lime-sulphur wash. By these applications 
large percentages of the scales were destroyed. The treatments 
were sufficiently effective in this respect to maintain the thriftiness 
of the trees and to keep the fruit crop fairly clean. On the basis 
of these results the miscible oils tested should not be used in weaker 
mixtures than one part to ten or fifteen parts of water. 
These sprays are simple to prepare, and have no sediment, and 
for these reasons are very convenient preparations for the treatment 
of old trees and small orchards. The cost of the miscible oils in 
